McCartney believes the stage is set today for Carroll to break his scoring duck for the Hammers.
The beanpole striker, on loan from Liverpool, was unhappy being subbed against Stoke on Monday and McCartney said: "He was disappointed to go off when he did.
"Andy is a great lad. Very down to earth. He gives 100 per cent every game and gives defenders problems. I'm sure it won't be long before he gets that first goal for us and, once he does, I'm sure he'll go on a run and get a few."